Dried spent yeast (DSY) and its hydrolysate (DSYH) were used as low-cost nitrogen supplements to improve ethanol production from sweet sorghum juice by Saccharomyces cerevisiae NP01 under very high gravity (VHG) fermentation (280 g·L −1 of total sugar) conditions. The supplemented DSY and DSYH concentrations were 11, 16 and 21 g·L ). The use of DSYH at the same DSY concentration improved ethanol productivity (Q p ), but not P E and Y p/s . The ethanol production efficiencies of the juice under DSY and DSYH supplementations were markedly higher than those without nutrient supplementation. However, the P E and Q p values of the juice , respectively.